Attacks on sorely-needed increases in state tax revenues often include the unproven claim that tax hikes will drive large numbers of households — particularly the most affluent — to other states. The same claim also is used to justify new tax cuts. Compelling evidence shows that this claim is false. The effects of tax increases on migration are, at most, small — so small that states that raise income taxes on the most affluent households can be assured of a substantial net gain in revenue.